Django正在获取与对象相关的记录列表（带有FK）-未正确呈现模板

我试图在这里遵循前面的问题：

但似乎无法让它发挥作用

我有主人的名单，但没有宠物的名字。html代码似乎没有执行第二个FOR循环。有什么想法吗

型号.py

class Teacher(models.Model):
        teacher = models.CharField(max_length=300, verbose_name="teacher")

        def __unicode__(self):
          return self.teacher

class Owner(models.Model):
        relevantteacher = models.ForeignKey(Teacher, verbose_name="teacher")       
        owner = models.CharField(max_length=300, verbose_name="owner")

        def __unicode__(self):
          return self.owner

class PetName(models.Model):
        relevantowner = models.ForeignKey(Owner, verbose_name="owner")
        pet_name = models.CharField(max_length=50, verbose_name="pet Name")

    def __unicode__(self):
      return self.pet_name

def ownersandteachers(request):   
   owners = Owner.objects.all()

   context = {'owners': owners}
   return render(request, 'ownersandpets.html', context)

视图.py

class Teacher(models.Model):
        teacher = models.CharField(max_length=300, verbose_name="teacher")

        def __unicode__(self):
          return self.teacher

class Owner(models.Model):
        relevantteacher = models.ForeignKey(Teacher, verbose_name="teacher")       
        owner = models.CharField(max_length=300, verbose_name="owner")

        def __unicode__(self):
          return self.owner

class PetName(models.Model):
        relevantowner = models.ForeignKey(Owner, verbose_name="owner")
        pet_name = models.CharField(max_length=50, verbose_name="pet Name")

    def __unicode__(self):
      return self.pet_name

def ownersandteachers(request):   
   owners = Owner.objects.all()

   context = {'owners': owners}
   return render(request, 'ownersandpets.html', context)

模板

{% for i in owners %}
    {{ i.owner }} has pets:<br />
    {% for v in owners.petname_set.all %} //this doesn't seem to be executing
     - {{ v.pet_name }}<br />
    {% endfor %}
{% endfor %}

{%for i in owners%}
{{i.owner}}有宠物：

{%for v in owners.petname_set.all%}//这似乎没有执行
-{{v.pet_name}}

{%endfor%}
{%endfor%}

您正在做什么

{% for v in owners.petname_set.all %}

你应该去哪里

{% for v in i.petname_set.all %}

owners

是查询集，但您需要为查询集中的单个对象获取

petname\u集

，在本例中，该对象为

i

另外，如果

I.petname\u set

存在，我建议进行条件检查。如果没有，则不要显示

有宠物：

文本

{% for i in owners %}
    {{ i.owner }} 
    {% if i.petname_set.count %} has pets:<br />
        {% for v in i.petname_set.all %} //this doesn't seem to be executing
         - {{ v.pet_name }}<br />
        {% endfor %}
    {% endif %}
{% endfor %}

{%for i in owners%}
{{i.owner}}
{%if i.petname_set.count%}有宠物：

{%for v in i.petname_set.all%}//这似乎没有执行
-{{v.pet_name}}

{%endfor%}
{%endif%}
{%endfor%}